Electrical connector

ABSTRACT

A plug in electrical connector for receiving the plug end of a printed circuit board. The connector includes a housing means having a receptacle for receiving the plug end of a circuit board. The periphery of the receptacle is resilient for nonabrasively receiving the plug end of the printed circuit board and provides electrical contact with the plug end of the printed circuit board. A tension means is mounted in the housing means out of contact with the resilient peripheral boundaries of the receptacle urging the boundaries toward the plug end of the circuit board with a force sufficient to establish electrical contact between conductor paths extending along the receptacle and the conductor paths extending along the plug end of the circuit board. The connector is miniaturized and adapted to interconnect a plurality of circuits in an information storer to a plurality of circuits in a drive device without damage to such circuits.

ite s Kurt Kautmann;

Rudolf Jerney; Franz Wandinger, all of Munich, Germany Oct. 6, 1969 Oct.19, 197 1 Siemens Aktiengesellschatt Berlin and Munich,

[72] Inventors [21 Appl. No. [22] Filed [45] Patented [73] Assignee [32]Priority Oct. 9, 1968 [33] Germany [31] P18021301 [54] ELECTRICALCONNECTOR 10 Claims, 3 Drawing Figs.

Primary Examiner-Marvin A. Champion Assistant Examiner-Terrell P. LewisAttorney-Hill, Sherman, Meroni, Gross -& Simpson ABSTRACT: A plug inelectrical connector for receiving the plug end of a printed circuitboard. The connector includes a housing means having a receptacle forreceiving the plug end ofa circuit board. The periphery of thereceptacle is resilient for nonabrasively receiving the plug end of theprinted circuit board and provides electrical contact with the plug endof the printed circuit board. A tension means is mounted in the housingmeans out of contact with the resilient peripheral boundaries of thereceptacle urging the boundaries toward the plug end of the circuitboard with a force sufficient to establish electrical contact betweenconductor paths extending along the receptacle and the conductor pathsextending along the plug end of the circuit board. The connector isminiaturized and adapted to interconnect a plurality of circuits in aninformation storer to a plurality ofcircuits in a drive device withoutdamage to such circuits.

PATENTEUURT 1919?! 14,707,

SHEET 20? 2 lElLEtIlCAlL CONNECTOR This invention relates generally toplug in electrical connectors for printed circuit boards and morespecifically to electrical conductive receptacles nonabrasivelyreceiving electrical conductive paths extending along the plug ends ofprinted circuit boards.

A variety plug in electrical connectors receiving the plug ends ofprinted circuit boards are known. One such known connector includes aplurality of contact springs arranged adjacent to one another, in astrip form for contacting various electrical circuits. In this type ofconnector, the contact springs are designed in such a manner that theygenerate the necessary contact pressure on one side thereof and leadwires and the like are soldered onto the other side to provide anelectrical path away from the contact springs. The disadvantage of thistype of electrical connector is that the number and width of theelectrical paths are limited. The contact springs have to be thickenough and strong enough to provide the necessary soldering areas andcontact pressure and they must be separated by insulating parts to avoidshorts and the like. A further drawback of these known electricalconnectors is that they abrasively receive the plug end of the printedcircuit board and, of course, thereby wear out the electrical paths onthe plug end of the printed circuit board or on the contact springs.

Another known electrical connector includes a contact spring stripconsisting of two rails or bars swingably connected with one another andforming a fork. An insulating plate material is clamped between the tworails in such a way that circuit lines are pressed against the contactelements held on the bar. The contact elements of this type ofelectrical connector are formed in such a way that they are deformedunder the action of the contact of pressure so that the points ofcontact are shifted on the electrical circuit. In this matter theelectrical circuits become worn, naturally this is undesirable.

Another known electrical connector is arranged to provide the necessarycontact pressure after the plug end of the printed circuit board hasbeen inserted. One particular form of this type of electrical connectorsuggests that the two connecting portions to be joined and contact eachother at a particular angle. The contact pressure is then againgenerated by providing a straight-line pressure on the angularly joinedplug parts. Another form of this type of electrical connector utilizes arotary wedge or key to generate the necessary electrical contactpressure.

The common feature of these variously known electrical connectors is thedouble function of the resilient receptacle, which includes conductingthe electrical current and generating the required contact pressure.Since this requires the mutual insulation of the spring elements, thenumber of circuits lying adjacent to one another per unit length islimited. However, this is undesirable in present day technology whereinminiaturization requires greater density of circuits.

Accordingly, it is an important object of the instant invention toprovide a plug-in electrical connector overcoming at least some of theaforesaid disadvantages and providing nonabrasive electrical contactbetween multicircuit devices.

It is yet another object of the invention to provide an electricalconnector which nonabrasively receives the plug end of a printed circuitboard and thereafter provides the necessary electrical contact pressure.

It is yet another object of the present invention to provide an improvedelectrical connector of minimal size and having nondamaging electricalcontacts between a plurality of electrical circuits.

In accordance with the principles of the invention, a housing means isprovided having a cavity which is lined with an electrical contact meansand this electrical contact lining is urged toward the center of thecavity and a tensioning means is mounted on the housing means out ofcontact with the lining means for further urging of the lining meanstoward the center of the cavity.

Other and further objects, features and advantages of the presentinvention will become apparent to those skilled in the art from thefollowing description of the instant invention and the drawings attachedhereto and made a part hereof.

ON THE DRAWINGS FIG. l is essentially an elevated sectional view of anelectrical connector constructed in accordance with the principle of theinvention and receiving a pronged contact member;

FIG. 2 is essentially a partially cutaway plan view of the structureshown in FIG. 11; and

FIG. 3 is an essentially partial cutaway elevational side view withparts cut away illustrating another embodiment of an electricalconnector constructed in accordance with the principles of the inventionand receiving a prong contact member.

DESCRIPTION OF THE PREFERRED EMBODIMENT In accordance with theprinciples of the instant invention, the desired circuit paths (printedor otherwise provided) may be extremely and almost arbitrarily narrowsince the electrical contacts are not made or brought about by a specialplug device but by similarly narrow circuit paths. The contact pressureis distributed uniformly over all of the electrical contact areas sothat each such area is subjected to the same contact pressure. Thus, theinvention provides an electrical contact means having a plurality ofcircuits thereon, such as a copperlined etched foil, which ismechanically and electrically positively joined with a plurality ofcooperating circuits on a plug end of a printed circuit board, and iseasily detachable without damage to such circuits. The contact pressureprovided by the instant connector is preferably about 50 p. Further,there is no shifting or relative movement between the circuits on theconnector and on the plug member during the attachment or detachmentthereof. This is particularly important since generally the electricalcontact means comprises synthetic resinous plastic foils of about 5 pm.thick and having cemented or etched copper layers of about 17 pm. thickthereon to define the desired circuits and any shifting or abrasivemovement between such circuits would, naturally readily grind down orwear out the conductor layers and thereby destroy the circuits.

Preferably the electrical connectors of the instant invention areconstructed in such a manner that the plug end receiving receptacle hasa resilient boundary providing an electrical contact with the contactsurfaces extending along the plug end of the printed circuit board and atension means is mounted out of contact with such a resilientelectrically conductive peripheral boundary and urges the boundarytoward the plug end of the printed circuit board with a force sufficientto establish electrical contact between the boundary and the contacts onthe plug end of the printed circuit board. Further, in this manner theresilient boundary is able to compensate for any inequalities in thethickness of the conductor material defining the circuits on the plugsurface.

The electrical connector of the instant invention is particularly usefulto provide electrical connection between the word and bit lines emergingfrom a thin-layer storer and appropriate operating lines of a drivedevice. The electrical connector of the invention may be composedentirely of nonmagnetic material thereby avoiding a magnetic influenceon an information storer or the like. Preferably, such nonmagneticmaterials are selected from the group consisting of nonferrous metalsand resinous synthetic materials, i.e., plastics. Further, theelectrical connector of the instant invention is constructed as toprovide the desired nondestructive or nonabrasive electrical contactbetween a plurality of circuits while maintaining its total height below10 mm. This size dimension is of considerable importance inminiaturization and should not be underestimated since the prior artdevices fail to achieve such dimensrons.

Referring now to the drawings, wherein like reference numerals refer tolike parts, and first particularly referring to FIGS. 1 and 2, it willbe seen that a housing means I is formed from two matching shell halvesllc. As will be appreciated, the

housing means 1 may be constructed of a single-piece or two half-shellsas described. The housing means 1 has a cavity 1a formed therein and aconductive receptacle 1b extends within the cavity In to receive theplug end 9 of a printed circuit board. When the housing means isconstructed of two shell halves as shown, a clamp device 2 is providedto hold one of the edges of the shell halves together while leaving theopposed edges free for insertion of the plug end 9 of the printedcircuit board. The clamp device 2 may comprise a C-shaped spring memberfitting into outwardly opening recesses in the outer periphery of theshell halves. A plurality of such spring members arranged in end-to-endrelation may be provided where required. Of course, if desired, aunitary construction of housing means may be utilized and the clampdevice dispensed with.

An electrical contact means 4 in the form of a flexible conductor stripor band provides an electrical contacting path between the conductingsurfaces extending along the plug end 9 of a printed circuit board. Saidcontact means may be connected to an information storer, (not shown) tointerconnect a plurality of circuits to an appropriate drive deviceoutside the electrical connector. The electrical contact means 4 (orconductor strip) comprises a plastic foil or band carrying a pluralityof conductor circuits 11 along a surface thereof. The conductor strip 4extends along the interior of a contact pressure spring 3. The contactpressure spring 3 is generally in the form of a U-shaped spring and hasa pair of wavelike or undulating legs having outwardly turned outer endportions engaging facing notches in the interior walls of the shellhalves 1c of the housing 1. The flexible strip 4 is adhesively orotherwise secured to peaked portions of the waves of the U-shaped spring3. A contact pressure means 5 is provided at the base of the U-shapedspring 3 between the legs thereof, to separate the bight portion of theflexible conductor strip means 4 inside the cavity la. Preferably, thestrip means 4, the U-shaped spring 3, and the contact pressure means 5are all cemented together to form a single structure and for ease ofmanufacture may be preformed and inserted into the cavity as a singleunit. The tension device 3 is preferably in the form of a plurality ofspring leaves appropriately formed and having a width dimensionsufiicient to cover at least two adjoining circuit paths 11. In thismanner, any uneveness in the surface of the plug end 9 of the circuitboard or in the conductor circuit 11 on the flexible strip means 4 onboth sides of the connector are compensated for.

The electrical contact means or conductor strips 4 extend about the endsof the shell halves 1c and rearwardly along the outer sides thereof andmay be attached to the outer peripheral surfaces of the housing means 1by an appropriate means, such as screws. In order to protect the strips4 and provide a desired degree of stiffness for fastening purposes, twoHp plates 7 and 8, composed of, for example, hard paper plates or thelike are cemented about the portions of the strip 4 extending the shellhalves of the housing means 1.

The dimensions of the housing means cavity In and its resilientelectrically conductive peripheral boundaries, as defined by tensionmeans 3 and lining strips 4 allow the plug end 9 of the circuit board tobe nonabrasively received into the housing means cavity during theinsertion thereof into the receptacle lb. The circuit paths on the strip4 and on the plug end 9 are thus brought into current conductiveengagement with one another without the exertion of any contact pressurebetween such circuits paths.

The required electrical contact pressure is provided by moving a secondspring member 6, which in the embodiment shown, is in the form of aU-shaped spring, along the outer sides of the housing means 1 alongguide grooves 6a into engagement with outwardly opening notches at theouter ends of said guide grooves and urging the flexible contact strips4 toward the center of the receptacle. Of course, in removing the plugend 9 of the circuit board, the tensioning device 6 is first removed todiscontinue the contact pressure (i.e. about 50 P) and then the plug in9 of the circuit board is removed from the receptacle of the electricalconnector. Thereby any damage, such as by rubbing or abrasion, of thethin and very delicate conductor paths on the electrical contact means 4or on the plug end of the circuit board is prevented and the connectingoperation can be repeated as often as desired without damage to theconductor of the printed circuit.

It will be noted that the tension device 6, which in the embodimentshown is generally a U-shaped spring member having a center wall andupstanding sidewalls, has portions thereof, i.e., the sidewalls, ofsubstantially the same length as the cavity peripheral edges and therebyis able to provide uniform pressure along the entire cavity periphery.In this manner the pressure exerted by the U-shaped spring 3 by thecompressive effect of the U-shaped spring 6 is uniformly distributedonto the circuit paths. It will be appreciated that through appropriatedimensioning of the two U-shaped springs 3 and 6, any damagingdeformation of the U-shaped spring 3 or inequities in the pressurerelationships is avoided.

This type of construction for electrical connectors allows a relativelygreat variation in the thickness of the contacts of the plug end of thecircuit board with only a slight variation in the contact pressuregenerated between the plug member and electrical contact means of theconnector.

As shown in FIG. 2, appropriate guide strips 10 extend along oppositesides of the ends of the plug end 9 of the circuit board to guide andconfine of the connector in a manner well understood in the art.Conveniently, the guide strips 10 are attached to the housing 1 of theelectrical connector by any conventional means, as by a conventionalscrew fastener, secured to the projecting ends of the clamp 2.

Referring now to FIG. 3, wherein a plurality cutaway side view ofanother embodiment of plug in electrical connector constructed inaccordance with the principles of the invention is shown which utilizesa rotary key or wedge to provide the electrical contact pressure. Itwill be seen from FIG. 3 that a housing means 1 (which may be composedof two shell halves) is provided with a pair of lateral side plates 14.The sideplates 14 function as a bearing means for an eccentric device 13and for a contact pressure device 5. The sideplates 14 also function asguiding boundaries for the insertion of a plug end 9 of a circuit board.The eccentric 13 is movable in the directions indicated by the doubleheaded arrow so as to present one sur face thereof against a contactpressure key 15 and shift the key 15 in the direction of the spring ortension device 3. Of course, the eccentric 13 also has another surfaceportion whereby this pressure is released. In this manner the arching ordeformation of the tensioning device 3 is increased and the necessarycontact pressure is generated.

An elastic support 16 is provided between the contact pressure device 5and the electrical contact means or strips 4 lining the cavity la in thevicinity of the contact pressure key 15. The elastic member 16compensates for any slight change in length that the strips 4 undergoduring the generation of contact pressure by the movement of theeccentric 13. It will also be noted that this embodiment illustrates asomewhat different means for fastening the strips 4 to the housing means1, however, this does not affect the function of the connector of theinstant invention and need not be described in detail.

In summation, it will be seen that the instant invention providesimproved form of plug in electrical connector for receiving the plug endof a circuit board, comprising a housing means having a cavity formedtherein and a receptacle for the plug end of a circuit board extendingalong the cavity and defining an insertion axis along with the plug endof the circuit board is received, the receptacle has resilientelectrically conductive peripheral boundaries providing electricalcontact with the conductor path extending along the plug end of thecircuit board and the electrical connector; a contact pressure means inthe form of a U-shaped spring is mounted on the housing means out ofcontact with the resilient conductive receptacle urging the shell halvestoward the axis of the receptacle under a force sufficient to establishelectrical contact. An eccentric device is mounted on the housing meansand We claim: l. in a plug-in electrical connector for nonabrasivelyreceiving and connecting the plug end of a printed circuit board to atleast one flexible multiple conductor strip,

a housing having two shell halves having abutting engagement with eachother at one end thereof and having spaced facing walls forming acavity, the center of which deiines an insertion axis along which theplug end of the printed circuit board is inserted,

a U-shaped contact pressure means mounted in said cavity and having abase at the inner end of said cavity and parallel legs extending fromsaid base along said facing walls and having abutting engagement withsaid walls at the outer ends thereof,

at least one flexible multiple conductor strip extending along saidparallel legs in the general form of a U and leaving a plurality ofconductor paths facing each other and defining a plug receivingreceptacle, nd

other pressure means exerting pressure on said U-shaped contact pressuremeans and biasing said conductor strips into conducting engagement withconductor strips extending along the plug end of the printed circuitboard.

2. The plug-in electrical connector of claim 1,

wherein the shell halves are movable towards and from each other,

and wherein the other pressure means comprises a U- shaped springextending along opposite sides of said shell halves and biasing saidfirst lU-shaped pressure means and conductor strips into currentconducting engagement with the plug end of the circuit board.

El. The plug-in electrical connector of claim 2,

wherein the first U-shaped contact pressure means has wavelike legsextending from the base thereof having facing peaked portions engagingthe flexible multiconductor strip, and valley portions engaging saidwall portions of 45 said shell halves, and

wherein the outer end portions of said legs have interengagernent withsaid wall portions, to force said peaked portions toward the plug end ofthe circuit board by the compressive force exerted by said secondmentioned U-shaped spring.

41. The plug-in electrical connector of claim 2, including a C-shapedclamp holding the inner ends of aid shell sections together and in theregion of abutting engagement of said shell section with each other andaccommodating movement of said shell sections relative to each otherabout the region of abutting engagement of said shell sections.

5. The plug-in electrical connector of claim 2, including a resilientpressure strip extending along the inside of said multiconductor stripinto engagement with a base thereof and along the conductive surfacesthereof for a short portion of the length thereof.

b. The plug-in electrical connector of claim at,

wherein the conductor strip extends along the outer ends of said shellsections and rearwardly along the outer walls thereof, and

wherein insulating strips extend along opposite sides of saidmulticonductor strip extending along the outer sides of said shellsections and are secured to said shell sections.

7. In a plug-in-type electrical connector for receiving the plug end ofa printed circuit board having a plurality of conductor strips extendingtherealong and for connecting the conductors strips with at least oneflexible multiconductor ta e,

a housing having a closed end and an open outer en and having facinginterior walls defining the inner margins of said open outer end andforming a cavity to receive the printed circuit board,

a first U-shaped contact pressure means extending within said cavityalong said interior walls and having a base disposed adjacent the innerend of said cavity, and parallel legs extending along said interiorwalls,

abutment means abuttingly engaged by the outer ends of said legsadjacent the open end of said cavity,

at least one flexible multiconductor strip extending along the legs ofsaid pressure means having conductor paths facing each other anddefining a plug receiving receptacle,

a turnable eccentric member rotatably mounted in said housing adjacentthe inner end of said cavity and effective to exert pressure on saidbase of said U-shaped pressure means and flex said legs toward eachother to provide the required contact pressure between said conductorstrip and the conductor paths extending along said plug end of theprinted circuit board.

h. The plug in electrical connector of claim 7,

wherein the legs of said U-shaped contact pressure means are wavelikehaving peaks and valleys in which the peaks of the legs engage saidflexible multiconductor strip and the valleys engage said inner walls ofsaid housing,

whereby pressure on said base effected by operation of said eccentricmember flexes the peaked portions of said waves toward each other toprovide the required pressure to effect contact between saidmulticonductor strips and contact paths extending along the plug end ofthe circuit board.

9. The plug-in electrical connector of claim ll, including a blockslidably mounted in said cavity between said sidewalls and interposedbetween said eccentric and the base of said U- shaped contact pressuremeans.

ill. The plug-in electrical connector of claim h, wherein the housing iscomposed of a nonmagnetic material selected from the group consistingessentially of nonferrous metals and synthetic resinous materials.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. DatedOctober 19, 1971 Inventor s Kurt Kaufmann et al It is certified thaterror appears in the above-identified patent and that said LettersPatent are hereby corrected as shown below:

Column 1, line 7, after "variety", insert --of".

Column 3, line 10, after "into", insert "appropriate";

line 40, change "tension device" to --U-shaped spring; line 41,after"leaves", insert "arranged in end-to-end relation along the housing1 and Column 4, line 6, change "conductor" to --conductors--.

Column 5, line 27, change "leaving" to --having--;

line 28, change "nd" to --and--.

Column 6, lines 15 and 16, change "conductors" to --conductor- (SEAL)Attest:

EDWARD M.FLETCHER,JR. Atteeting Officer ROBERT GOTTSCHALK Commissionerof Patents EM F'O-1050 {10-69) USCOMM-DC 60376-F69 U 5 GOVERNMENTPRINTING OFFICE I969 0-356-33i

1. In a plug-in electrical connector for nonabrasively receiving andconnecting the plug end of a printed circuit board to at least oneflexible multiple conductor strip, a housing having two shell halveshaving abutting engagement with each other at one end thereof and havingspaced facing walls forming a cavity, the center of which defines aninsertion axis along which the plug end of the printed circuit board isinserted, a U-shaped contact pressure means mounted in said cavity andhaving a base at the inner end of said cavity and parallel legsextending from said base along said facing walls and having abuttingengagement with said walls at the outer ends thereof, at least oneflexible multiple conductor strip extending along said parallel legs inthe general form of a U and leaving a plurality of conductor pathsfacing each other and defining a plug receiving receptacle, nd otherpressure means exerting pressure on said U-shaped contact pressure meansand biasing said conductor strips into conducting engagement withconductor strips extending along the plug end of the printed circuitboard.
 2. The plug-in electrical connector of claim 1, wherein the shellhalves are movable towards and from each other, and wherein the otherpressure means comprises a U-shaped spring extending along oppositesides of said shell halves and biasing said first U-shaped pressuremeans and conductor strips into current conducting engagement with theplug end of the circuit board.
 3. The plug-in electrical connector ofclaim 2, wherein the first U-shaped contact pressure means has wavelikelegs extending from the base thereof having facing peaked portionsengaging the flexible multiconductor strip, and valley portions engagingsaid wall portions of said shell halves, and wherein the outer endportions of said legs have interengagement with said wall portions, toforce said peaked portions toward the plug end of the circuit board bythe compressive force exerted by said second mentioned U-shaped spring.4. The plug-in electrical connector of claim 2, including a C-shapedclamp holding the inner ends of aid shell sections together and in theregion of abutting engagement of said shell section with each other andaccommodating movement of said shell sections relative to each otherabout the region of abutting engagement of said shell sections.
 5. Theplug-in electrical connector of claim 2, including a resilient pressurestrip extending along the inside of said multiconductor strip intoengagement with a base thereof and along the conductive surfaces thereoffor a short portion of the length thereof.
 6. The plug-in electricalconnector of claim 4, wherein the conductor strip extends along theouter ends of said shell sections and rearwardly along the outer wallsthereof, and wherein insulating strips extend along opposite sides ofsaid multiconductor strip extending along the outer sides of said shellsections and are secured to said shell sections.
 7. In a plug-in-typeelectrical connector for receiving the plug end of a printed circuitboard having a plurality of conductor strips extending therealong andfor connecting the conductors strips with at least one flexiblemulticonductor tape, a housing having a closed end and an open outer endand having facing interior walls defining the inner margins of said openouter end and forming a cavity to receive the printed circuit board, afirst U-shaped contact pressure means extending within said cavity alongsaid interior walls and having a base disposed adjacent the inner end ofsaid cavity, and parallel legs extending along said interior walls,abutment means abuttingly engaged by the outer ends of said legsadjacent the open end of said cavity, at least one flexiblemulticonductor strip extending along the legs of said pressure meanshaving conductor paths facing each other and defining a plug receivingreceptacle, a turnable eccentric member rotatably mounted in saidhousing adjacent the inner end of said cavity and effective to exertpressure on said base of said U-shaped pressure means and flex said legstoward each other to provide the required contact pressure between saidconductor strip and the conductor paths extending along said plug end ofthe printed circuit board.
 8. The plug in electrical connector of claim7, wheRein the legs of said U-shaped contact pressure means are wavelikehaving peaks and valleys in which the peaks of the legs engage saidflexible multiconductor strip and the valleys engage said inner walls ofsaid housing, whereby pressure on said base effected by operation ofsaid eccentric member flexes the peaked portions of said waves towardeach other to provide the required pressure to effect contact betweensaid multiconductor strips and contact paths extending along the plugend of the circuit board.
 9. The plug-in electrical connector of claim8, including a block slidably mounted in said cavity between saidsidewalls and interposed between said eccentric and the base of saidU-shaped contact pressure means.
 10. The plug-in electrical connector ofclaim 8, wherein the housing is composed of a nonmagnetic materialselected from the group consisting essentially of nonferrous metals andsynthetic resinous materials.